NASA to launch sounding rocket to check Earth's leaky atmosphere

New Delhi : NASA scientists recently came to know that the Earth's atmosphere is leaking into space. To confirm the finding, the space agency is all set to launch a sounding rocket to get a closer look at how the phenomenon is taking place.

Experts say that understanding atmospheric escape on Earth has applications all over the Universe, from predicting which far-off planets might be habitable, to piecing together how Mars became the desolate, exposed landscape it is today. Therefore, the VISIONS-2 (Visualizing Ion Outflow via Neutral Atom Sensing-2) mission will be blasted off on December 4.

For VISIONS-2 mission, the team will travel to Svalbard, a remote archipelago off the northern coast of Norway where dayside aurora can be found. VISIONS-2 is the first of nine sounding rockets launching over the next 14 months as part of the Grand Challenge Initiative, an international collaboration to explore the unusual portal between Earth and space.

Sounding rockets are unique among scientific spacecraft for their superior dexterity. It makes a brief targeted take off into space before falling back to Earth just a few minutes later. They can be carried to remote locations, where they are aimed and shot into short-term programme, like sudden formation of the aurora borealis.

The aurora play is fundamental drivers in the process of atmospheric escape, whereby planets, including Earth, gradually leak their atmosphere into space. "The Earth is losing weight," said Thomas Moore, a NASA space physicist.

"There have been enough observations to know that anywhere from a hundred to several hundred tonnes of the atmosphere is going into space every day," Moore said. Moore estimates that at that rate, the Earth will retain its atmosphere for a billion or so years. Scientists had long thought that oxygen, weighing in at 16 times the mass of hydrogen, was too heavy to escape Earth's gravity.

Conversely, the near-Earth space is crawling with much more Earth-borne oxygen than anyone had expected. The aurora is formed when energetic electrons, accelerated in the electric and magnetic fields in near-Earth space, crash into and excite atmospheric gases, which release bright hues of red, green, and yellow as they relax back to a lower energy state.

These disorderly electrons also create a gush of havoc in the process, including driving electric currents that heat the upper atmosphere in splotchy patches. In some cases, that heating is sufficient to give stray oxygen atoms enough energy to escape.

The current mission's precursor, VISIONS-1, launched from the Poker Flat Research Range in Alaska in 2013, where they studied oxygen outflow from Aurora that forms on Earth's night side, the part of the planet that is temporarily pointed away from the Sun.